Activation of mTOR coincides with autophagy during ligation-induced atrophy in the rat submandibular gland

Salivary gland atrophy is a common consequence of pathology, including Sjögren's syndrome, irradiation therapy and obstructive sialadenitis. During severe atrophy of the rat submandibular gland caused by excretory duct ligation, the majority of acinar cells disappear through apoptosis, whereas ductal cells proliferate and dedifferentiate; yet, the gland can survive in the atrophic state almost indefinitely, with an ability to fully recover if deligated. The control mechanisms governing these observations are not well understood. We report that ∼10% of acinar cells survive in ligation-induced atrophy. Microarray and quantitative real-time PCR analysis of ligated glands indicated sustained transcription of acinar cell-specific genes, whereas ductal-specific genes were reduced to background levels. After 3 days of ligation, activation of the mammalian target of rapamycin (mTOR) pathway and autophagy occurred as shown by phosphorylation of 4E-BP1 and expression of autophagy-related proteins. These results suggest that activation of mTOR and the autophagosomal pathway are important mechanisms that may help to preserve acinar cells during atrophy of salivary glands after injury

The assessment of oral dryness by photographic appearance of the tongue

Background Oral dryness or hyposalivation is a major clinical problem. Several chairside tests or visual inspections of the oral cavity have been proposed for the assessment. Objective To identify whether photographs of the tongue could be used to identify oral dryness. Material and methods Twenty-five dentists and 25 individuals with another academic background were recruited. They assessed the severity of the oral dryness of 50 patients, based on an intraoral picture of each patient. The oral dryness was quantified with a five-point Likert scale and the scores were subsequently compared with the salivary flow rate and the level of xerostomia of these patients. Results No relation was found between the unstimulated salivary flow rate of a patient and the average oral dryness score, determined by dentists (p = 0.260) as well as non-dentists (p = 0.806). Also no relation was found between the self-reported xerostomia level of the patient and the average dryness score assessed by the dentists (p = 0.171) or non-dentists (p = 0.477). Conclusion It does not seem possible to diagnose oral dryness by mere visual inspection of photographed tongues. Thus, for correct diagnosis of oral dryness further clinical investigation of the oral cavity and collection of saliva is indicated

Clinical oral dryness score: evaluation of a new screening method for oral dryness

The purpose of this study was to explore the association of the clinical oral dryness score (CODS) with salivary flow rates, xerostomia inventory (XI), and bother index (BI). 147 patients were screened using CODS, which determined 10 features of oral dryness. Each feature contributed 1 point, and the total score varied from 0 to 10. Unstimulated (UWS), chewing-stimulated (CH-SWS) and acid-stimulated (A-SWS) whole salivary flows and the XI and BI were measured. Associations were explored with a bootstrapped Spearman rank correlation test (1000 × bootstrapping). Based on unstimulated salivary flow, 55 patients were classified as hyposalivators, 31 as low salivators, 48 as normosalivators and 13 as high salivators. Median CODS in the hyposalivation group was 5 (IQR 3–6) compared with 3 (IQR 2–5) in the low salivation group, 2 (IQR 1–4) in the normal salivation group and 2 (IQR 1–2.5) in the high salivation group. Significant associations between CODS and the other parameters were only found in the hyposalivation group between CODS and UWS (ρ(53) = − 0.513; p < 0.01), between CODS and CH-SWS (ρ(53) = − 0.453; p < 0.01), between CODS and A-SWS (ρ(53) = − 0.500; p < 0.01), CODS and XI (ρ(53) = 0.343; p < 0.001) and between CODS and BI (ρ(53) = 0.375; p = 0.01). In patients with hyposalivation, CODS is associated with unstimulated and stimulated salivary flow and XI and BI. CODS alone or a combination of CODS with a subjective measure, such as the XI or BI, could be recommended during routine clinical assessment to detect hyposalivation